1. Field of the Invention
More particularly, the invention relates to such optical projectors comprising: a luminous data source and means for projecting and collimating light from the source comprising: a first lens arrangement arranged to receive light from the source; a second lens arrangement having an optical axis inclined with respect to the optical axis of the first lens arrangement; and between the first and second lens arrangements a reflector means for deflecting rays from the first lens arrangement to the second lens arrangement for transmission thereby; said reflector means comprising a body of light refractive material having a light input face via which light enters the body from an output surface of the first lens arrangement and two further faces which define a wedge-shaped portion of the body extending across a light input surface of the second lens arrangement, one of two said further faces having a mirror coating thereon and the wedge angle and orientation of the wedge-shaped portion of the body being such that light entering the body from the first lens arrangement undergoes critical angle reflection at the other of said two further faces to the said one further face from whence, after reflection, it is transmitted, without substantial reflection, by the said other further face to the second lens arrangement for transmission thereby.
2. Description of Related Art
Such an optical projector, hereinafter referred to as an optical projector of the kind specified, forms the subject of U.S. Pat. No. 4,611,877 filed on 30 Aug. 1985 in the name of Stafford Malcolm Ellis.